01 keep 
02 keep        <- gets discarded by your code.
03 keep        <- gets discarded by your code.
04 keep        <- gets discarded by your code.
05 keep        <- gets discarded by your code.
06 keep        <- gets discarded by your code.
07 discard B5
08 discard B4
09 discard B3
10 discard B2
11 discard B1
12 somepat
13 somepat

##</code><code>##

    'd!'      => \$delete,

##</code><code>##

perl dellines.pl -i somepat -d > someconfile